<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>图形</title>
    <style>
        .myDiv {
            width: 0;
            height: 0;
            border-top: 50px solid cadetblue;
            border-right: 50px solid transparent;
            border-left: 50px solid transparent;
        }

        .down {
            width: 0;
            height: 0;
            border-top: 50px solid skyblue;
            border-right: 50px solid transparent;
            border-left: 50px solid transparent;
        }
    </style>
</head>
<body>
<div class="myDiv"></div>
<div class="down"></div>
</body>
</html>